01782nas a2200205 4500008003900000022001400039245008700053210006900140260001200209300001100221490000700232520110700239653003601346653001901382653004001401100002101441700001801462700001901480856007701499 2014 d a0963-025200aAsymmetric particle fluxes from drifting ionization zones in sputtering magnetrons0 aAsymmetric particle fluxes from drifting ionization zones in spu c04/2014 a0250070 v233 a
Electron and ion fluxes from direct current and high-power impulse magnetron sputtering (dcMS and HiPIMS) plasmas were measured in the plane of the target surface. Biased collector probes and a particle energy and mass analyzer showed asymmetric emission of electrons and of singly and doubly charged ions. For both HiPIMS and dcMS discharges, higher fluxes of all types of particles were observed in the direction of the electrons' E x B drift. These results are put in the context with ionization zones that drift over the magnetron's racetrack. The measured currents of time-resolving collector probes suggest that a large fraction of the ion flux originates from drifting ionization zones, while energy-resolving mass spectrometry indicates that a large fraction of the ion energy is due to acceleration by an electric field. This supports the recently proposed hypothesis that each ionization zone is associated with a negative–positive–negative space charge structure, thereby producing an electric field that accelerates ions from the location where they were formed.
10aInstrumentation and measurement10aPlasma physics10aSurfaces, interfaces and thin films1 aPanjan, Matjaž1 aFranz, Robert1 aAnders, André uhttps://facades.lbl.gov/publications/asymmetric-particle-fluxes-drifting